The ADDF Highlights Encouraging Progress Toward Targeting Multiple Alzheimer's Pathologies in Biogen's Phase 2 Tau Study

Findings point to continued momentum toward combination therapies that target the full pathobiology of the disease

NEW YORK, May 14, 2026 /PRNewswire/ -- Today, Biogen announced topline results from the Phase 2 CELIA study of diranersen, an investigational therapy designed to target tau in people with early Alzheimer's disease. While the study did not meet its primary endpoint, Biogen reported reductions in tau and signals of slowed cognitive decline and plans to advance the drug into further trials.

"These results reflect the growing momentum and diversification across the Alzheimer's field," said Isobel Coleman, Chief Executive Officer of the Alzheimer's Drug Discovery Foundation (ADDF). "With disease-modifying therapies for Alzheimer's now available, the next step is to build on that foundation with new approaches that can expand treatment options and move us closer to precision medicine. That is the next generation of science the ADDF has long worked toward, and these results are an encouraging signal that the Alzheimer's pipeline is becoming broader, deeper, and more ambitious."

"We've seen meaningful progress with amyloid-targeted therapies, and these results suggest the field is moving closer to doing the same for tau," said Howard Fillit, MD, Co-Founder and Chief Science Officer of the ADDF. "While we need to see the full data, diranersen is the first therapy of its kind to reach this stage, offering early proof of concept that reducing tau could have both biological and clinical effects. A successful tau-targeting therapy would be a major milestone for the field, moving us closer to a future where we can treat multiple core Alzheimer's pathologies in combination to address the full complexity of this disease."

With two disease-modifying anti-amyloid therapies now available, tau presents an important opportunity for expanding Alzheimer's treatment options. These results come as the Alzheimer's pipeline continues to grow and evolve, with 75% of current trials now aimed at pathways beyond amyloid and tau, including inflammation, metabolic dysfunction, and oxidative stress. This broadening range of targets is critical to the future of Alzheimer's care, as the field moves toward combination approaches that can address multiple underlying causes of the disease in tandem.

Topline data from the CELIA study will be presented at the upcoming Alzheimer's Association International Conference (AAIC), taking place July 12-16, 2026, in London.

About The Alzheimer's Drug Discovery Foundation (ADDF)

Founded in 1998 by Leonard A. and Ronald S. Lauder, the Alzheimer's Drug Discovery Foundation is dedicated to rapidly accelerating the development of drugs to prevent, treat, and cure Alzheimer's disease. The ADDF is the only public charity solely focused on funding the development of drugs for Alzheimer's, employing a venture philanthropy model to support research in academia and the biotech industry. The ADDF's leadership and contributions to the field have played a pivotal role in bringing the first Alzheimer's PET scan (Amyvid®) and blood test (PrecivityAD®) to market, as well as fueling the current robust and diverse drug pipeline. Through the generosity of its donors, the ADDF has awarded nearly $400 million to fund 792 Alzheimer's drug development, biomarker, and prevention programs in 21 countries. To learn more, please visit: http://www.alzdiscovery.org/.

SOURCE Alzheimer's Drug Discovery Foundation